1. Field of the Invention
The present invention relates to the field of aeronautical turbine engines and is aimed in particular at the air inlet of the turbine engine, the latter comprising the engine itself and the nacelle in which it is housed.
2. Description of the Related Art
A turbine engine generally comprises a gas generator formed of one or more sets of rotors rotating about one and the same axis. Each set, known as a spool, is made up of a compressor and of a turbine which are usually connected by a shaft or drum, and are arranged one upstream and the other downstream of a combustion chamber in relation to the flow of gases through the engine. Associated with this gas generator is a fan or a simple or multiple set of fan blades that it drives.
When the rotor of the fan or set of fan blades is positioned in front of the engine, the air inlet of the generator is situated downstream of this rotor. Foreign bodies, such as birds, hail, water and stones, liable to be absorbed by the generator are at least partially slowed or halted by the front rotor which, because of its inertia and its size, partially forms a screen, or are deflected by a centrifugal effect of the fan toward the secondary flow path. Such protection does not exist on engines the fan or set of fan blades rotor of which is not positioned upstream of the gas generator air inlet.
Such is the case of an unducted fan, or UDF, engine or of an “open rotor” engine. This type of engine comprises a pair of sets of fan blades, which are contrarotatory, and arranged radially on the outside of the nacelle enveloping the generator, in line with two turbine impellers by which they are directly driven. The gas generator is a single flow generator. This type of engine is discussed in the patent application FR 2 606 081 in the name of the Applicant company.
One solution might be to strengthen the first compressor stages, but such reinforcement would lead to a sizing of the elements which is somewhat unfavorable in terms of mass and size, because these need to be capable of withstanding direct impacts.